A study of differences in classification of COPD patients with CAT or mMRC

Objective Chronic obstructive pulmonary disease (COPD) is one of the most important diseases in the world.In the 2011 new version of the GOLD Guide, a new system was used to classify COPD patients.The aim of study was to investigate the agreement between COPD risk group classifications using COPD assessment (CAT) or modified Medical Research Council (m MRC) and severity grades or past-year exacerbations.Physical activity across was examined and analyzed. Methods One hundred and sixty patients with stable COPD were classified into risk group A-D.CAT and m MRC were completed.Severity grades Ⅰ-Ⅳ were determined using spirometry and the number of past-year exacerbations was recorded.To test the interrater agreement, Cohen's Kappa was calculated.Daily physical activity was measured by Mini arm band. Results Using CAT, 105 patients were in high-symptom groups (B and D).With m MRC, 61 patients (41.25%) were in groups B and D.Using severity gradesⅠ-Ⅳ, 70 (43.75%) of patients were in high-exacerbation risk groups C and D.With past-year exacerbations, 76 (47.5%) patients were in C and D.Interrater agreement between CAT and m MRC was fair (r=0.45, P < 0.001), severity grades and past year-year exacerbation was also fair.Daily steps were reduced in risk groups B and C + D compared to A (P < 0.1), using either classification. Conclusion When classifying COPD patients into risk groups A-D, the use of CAT or m MRC and severity grades or past-year exacerbations can't provide equal results.Daily steps decreased with increasing COPD risk groups.